Method and apparatus for maintaining uniform temperature in frozen masses



Dec. 16, 1952 w. L. MORRISON 2,621,486

METHOD AND APPARATUS FOR MAINTAINING UNIFORM TEMPERATURE IN FROZENMASSES Filed Oct. 20, 1945 2 SPEETS-SI'IEET 1 Inventor flttorneya Dec.16, 1952 w g sou 2,621,486

METHOD AND APPARA US FDR MAINTAINING UNIFORM TEMPERATURE IN FROZENMASSES Filed 001'" 20, 1945 Z'SHEETSSHEET 2 .A/orrz'aan fl tiara/6 14Valiant 57 P Patented Dec. 16, 1952 METHOD AND APPARATUS FOR MAINTAIN-ING UNIFORM TEMPERATURE IN FROZEN MASSES Willard L. Morrison, LakeForest, Ill.

Application October 20, 1945, Serial No. 623,507

3 Claims. 1

My invention relates to an improved refrigeration assembly for shippingpurposes and to an improved method of refrigerated shipping.

One purpose is to provide an improved means for and method of shippingpre-cooled materials which are initially reduced to a very lowtemperature and are thereafter shipped or stored for substantial periodswithout further cooling.

Another purpose is to provide an improved means of and method foremploying the initial super-chilling of materials as the cooling mediumfor maintaining them at a satisfactory low temperature during a periodof shipping or storage or both.

Another purpose is to provide an improved means of and method ofshipping refrigerated materials.

Another purpose is to provide an improved shipping assembly forrefrigerated materials.

Another purpose is to provide improved containers in which materials maybe shipped while being kept at low temperatures.

Another purpose is to provide an improved shipping method and assemblyadaptable for shipping refrigerated materials in railroad cars, trucks,airplanes, sh ps and the like.

Other purposes will appear from time to time in the course of thespecification and claims.

The invention is illustrated more or less diagrammatically in theaccompanying drawings wherein:

Figure 1 is a transverse vertical section;

Figure 2 is a section on the line 2-2 of Figure 1;

Figure 3 is a transverse vertical section illustrating a variantprocedure; and

Figure 4 is a longitudinal vertical section illustrating a variantprocedure.

Like parts are indicated by like symbols throughout the specificationand drawings.

Referring to the drawings, and first to the form of structureillustrated in Figures 1 and 2, I illustrate an outer insulatedcontainer which in the drawings is shown as a relatively thick walledfreight car body. I illustrate for example a structure including outerwalls I, inner walls 2 and any suitable intermediate insulation. I mayfor example employ blocks or cartons 3 filled with a suitable insulatingmaterial. Any suitable access means may be provided and I illustrate forexample a bodily removable car top 4 which may be similarly formed andinsulated. The car bottom 5 is also insulated. Preferably in a freightcar of standard 40 ton size I may provide about 7" of insulation of thematerial having the effect or insulating quality of Santocel. It will beunderstood, however, that any suitably insulated container may beemployed. Whereas I illustrate my method as carried out by theemployment of a car body mounted for example on flanged wheels 6 ridingon rails i, it will be understood that I may employ a body or insulatedcontainer separable from the running gear, or applicable to othersupports. I may for example employ an insulated container which may bebodily positioned in an airplane or in a ship.

Within the outer insulated body or housing I illustrate a plurality ofseparate containers which may be filled with the material to be shipped.Each said container may for example be formed of walls of materialhaving heat conductivity. In Figs. 1 and 2, I illustrate, for example,containers having plane top and bottom walls It, H, plane end Walls I 2and corrugated interfitting side walls l3,the walls all being formed ofaluminum or some other material having advantageous heat conductingcharacteristics. One of the walls, such as the top wall t, may be maderemovable to permit insertion and removal of material. Whereas thecorrugated side Walls are advantageous as increasing the heat transferarea between adjacent containers, and also for increasing the stiffnessof the structure when supported by the ends, it will be understood thatplane walls may be substituted if desired. What is essential is that thewalls of adjacent packages or containers shall be in intimate contactover a maximum area, in order to maintain so far as possible, uniformtemperature conditions within the entire mass of material housed in thecar body or outer housing. Preferably the containers are so proportionedthat every container in the car loading is in contact with theinsulation adjacent to, or in one of the side walls of the car. Thus, inFig, 1 I illustrate the containers which may be indicated as A, asextending from the inner side wall member 2 to the center of the car asat B. Thus substantially uniform heat transfer conditions exist,throughout the mass, between the individual containers and theinsulation of the outer container or housing-or car body in which theyare housed. It is also important that the parts are so proportioned thatthe containers fit snugly together and contact both each other and theinsulation of the car side bottom and end walls. In this connection itis advantageous, although not strictly necessary, to have the roof ofthe car bodily removable, so that the individual containers may belowered into the interior of the car body and stacked in properposition.

A somewhat less efficient method of maintain ing the desired uniformityof temperature conditions throughout the mass is to employ interveninglayers of material having high heat conductivity characteristics. Thusin Fig. 3 I may arrange the individual containers B, of somewhat lesslength than the containers A of Figs. 1 and 2, in three tiers, withintervening layers 25 of a heat conducting metal, such as aluminum,extending from end to end of the car and in contact with the upper andlower walls of the car. In the form of Fig. l I illustrate similartransverse elements 2! which extend from side to side of the car andcontact also the top and bottom. The individual packages or containers Cof Fig. 4 may be made of plane sheets of aluminum or of other material.For example, where packages 01' masses packed inpaper are handled, paperpackages may be so arranged as also to contact transversely extendingheat conductivity elements 21. Whereas I have illustrated such elementsas spaced apart in Fig. 4, by the width of two stages of packages orcontainers, they may be arranged between each row or even may be morewidely spaced, depending upon the needs of the particular substancehandled.

It will be realized that whereas I have described and illustrated apractical and operative device,

nevertheless many changes may be made in the size, shape, number anddisposition of parts without departing from the spirit of my invention.I

therefore wish my description and drawings to be taken as in a broadsense illustrative or diagrammatic, rather than as limiting me to myprecise showing, and as showing examples of mechanisms which can be usedto carry out my procedure.

The use and operation of the invention are as follows:

The procedure followed in connection with the employment of the shippingassembly herein shown is as follows. The outer container or car bodyitself is initially reduced to alow temperature. It may for example bereduced to a temperature of the order of 20 degrees below zero or lower,or the inner space or the inner walls of the car may be thoroughlychilled, to a similar temperature, without at the same time reducing theexterior temperature of the car to any such degree. The individualcontainers or packages are filled or formed, and are not themselvesinsulated. The inner containers are preferably of high heat conductingmaterial, such as sheet metal aluminum plate or the like. The materialis superchilled, in said containers, to temperatures substantially lowerthan that of Dry Ice. Or the materials may be so processed before beinginserted into the individual containers, that the containers themselveswill shortly be chilled to the desired low temperature by the coldmaterial with which they are charged. The containers are then stacked orarranged in the car, preferably being disposed, as shown in Fig. 2, withsome part of each container in contact with an inner face of an exteriorwall of the outer housing. This, in connection with the high heatconductivity of the container walls, causes the entire mas to warm upmore evenly as heat is conducted inwardly through the outer housing thanwould be otherwise the case. Thus the warming up of the entire body offood within the car or outer housing permits the outer portions of thefood or other material to arrive at destination at substantially thesame temperature as the food or material of the inner part of the load.An important characteristic of my method is the handling of a large bulkof material, surrounded by an adequate outside housing of good heatinsulating characteristics, under conditions which maintain asubstantially even temperature throughout the entire mass of materialshipped or stored. In Figs. 1 and 2 I obtain this result by maintainingthe individual sub-containers in good heat transfer relationship witheach other, and with the outer housing. Somewhat less efficient arearrangements such as shown in Figs. 3 and 4, in which sheet members 20or 2! of high heat conductivity pass through the body of frozen food ormaterial, in such spacing as to cause the entire mass to warm upgenerally evenly. Where separate heat conducting plate members areemployed, of aluminum or other suitable material, the material in theindividual packages may be separated from the plate members by outerwalls or layers having a minimum resistance to the passage of heat. Oilpaper, or thin board, or sheet metal, or any other suitable material maybe employed for the individual sub-containers or packages.

In applying my method to a freight car of standard size I may employ ahollow walled body with a suitable insulating material between thewalls. I may for example apply a layer of 7" 0i Santocel insulation. Theinsulation is tamped between the walls, or applied by packing in car.-tons, as shown in one wall of Figure 1. The employment of separatecartons prevents any escape of the insulating material from the interiorof the cartons. It may also be advantageous to employ flocks on theexterior surface of the cartons.

Whereas as shown in Fig. 3 I may, if necessary, employ an intermediaterow of packages B which do not engage the side walls, these packageswill be maintained in contact either with longitudinally extending heattransfer plates 2B, or with transversely extending heat transfer plates2|, the latter being shown in Fig. 4.

A general characteristic of my method is to superfreeze the mass ofmaterial in such fashion that when the car or other outside containerstarts on its trip the entire mass of material r within the outercontainer or car body is initially at an exceedingly low temperature, atemperature which may be lower than that of Dry Ice. This mass ofinitially supercooled material constitutes the sole refrigerating mediumemployed during shipment. During shipment, and during subsequentstorage, until the load is opened, the transverse heat conductingmembers 20 and 21, or the heat conducting walls of the containers Aserve to maintain a substantially uniform temperature conditionthroughout the mass. This uniform temperature condition is favored alsoby the arrangement of containers A as shown in Figs. 1 and 2, in whicheach container itself engages a wall of the surrounding outer housing.

Whereas my method may be applied advantageously to freight cars it willbe understood that it may also be applied to motor trucks, and toshipping containers which are readily movable and may be shipped byairplane or by boat. Where a large number of such containers areemployed, as in boat cargoes, the outside containers, with preferably ofplane exteriors, may abut against each other in order to limit or reducethe outer surfaces of the entire mass which are exposed to ambienttemperature. By employing rectangular containers with flat tops, theouter containers themselves may be stacked one upon the other.

Where my method is applied to ordinary railroadtransportation, it isadvantageous to employ 5 a freight car body as the container. Asindicated in Figs. 1 and 2 I illustrate the roof of the freight car bodyas removable. stood that any other means for obtaining access to theinterior of the freight car body may be employed.

I claim:

1. In combination, a receptacle having a heat insulating outer housing,a plurality of separate fluid tight metal boxes so shaped that they maybe assembled into a compact mass within the housing substantiallycompletely filling it, each box containing a mass of frozen materialsubstantially completely filling the box at a temperature substantiallybelow zero, each box being in contact throughout its entire surface withthe boxes around it except where a box may be in contact with a wall ofthe housing, separate heat conducting means within the housing incontact with the walls thereof and extending throughout the mass incontact with at least one wall of the boxes adjacent to it.

2. In combination, an insulated receptacle having heat conductive platesextending across the area thereof between the walls and in contact withthe walls, a plurality of metallic boxes, each substantially filled bymaterial, the temperature of which is substantially below zero, saidboxes being contained within the housing and in contact with at leastone Wall of the housing or the conducting member and each surface ofeach box being in direct heat conductive contact with the surface of thebox adjacent to it to insure a di- It will be underrect flow of heatthroughout the entire mass both vertically and horizontally indirections perpei dicular to the walls of the container.

3. The method of preserving food and the like which consists inassembling a mass of food, subdivided into a plurality of separateabutting bodies, all at a temperature substantially below zero F.,enclosing the assembled bodies of food in the absence of any otherrefrigerant in an insulated zone, conducting heat through the mass alongthe boundaries between the abutting food bodies at a substantiallyuniform rate, higher than the normal rate of heat fiow within each body,to maintain uniform temperature conditions throughout the entire mass asthe temperature of the mass rises.

WILLARD L. MORRISON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 973,082 Smith Oct. 18, 19101,765,591 Kellett June 24, 1930 1,825,643 Martin Sept. 29, 19311,929,511 Mulkey Oct. 10, 1933 2,007,154 Bowes July 9, 1935 2,203,033Spiegl June 4, 1940 2,260,450 Guinane Oct. 28, 1941 2,393,245 HadsellJan. 22, 1946

